The present invention relates to motor vehicle seat backs.
More particularly, the invention relates to a motor vehicle seat back which comprises firstly a rigid frame having first and second side uprights and top and bottom cross-members interconnecting the first and second side uprights, and secondly a resilient supporting sheet fixed to the rigid frame and placed so as to come directly into contact with the back of a user.
In this type of back, the side uprights and the top and bottom cross-members forming the rigid frame are constituted by tubes, and the resilient supporting sheet is fixed directly to the inner periphery of the frame. The supporting sheet is therefore substantially in the form of a rectangle and all around its outer periphery it has fasteners for cooperating with complementary members, correspondingly disposed all around the inner periphery of the rigid frame. It will therefore be understood that fitting the supporting sheet to the frame requires the fasteners of said sheet to be fastened one after another to the complementary members of the rigid frame, thereby complicating assembly of the back and considerably increasing the time and cost of assembly.
An object of the present invention is to mitigate the above-mentioned drawbacks.
The invention achieves its object by the fact that the supporting sheet has a front face and a rear face, each having respective top and bottom edges and respective first and second side edges, said front and rear faces being secured to each other firstly via their top and bottom edges, and secondly via the first side edges so that the supporting sheet forms a bag for fitting onto the rigid frame by passing over the first side upright and covering the top and bottom cross-members and the first side upright, and by the fact that the second side edges of the front and rear faces of the resilient supporting sheet are fixed to the second side upright.
By means of these dispositions, the resilient supporting sheet which forms a bag can be fitted directly onto the rigid frame via one of its side uprights, and then needs to be fixed only to the other side upright, thereby making it possible to simplify assembly of the seat back for fitting to a seat proper of a vehicle seat, and considerably reducing the time required for said assembly.
In preferred embodiments of the invention, use may optionally be made of one or more of the following dispositions:
the second side upright is constituted by a side plate of depth, as measured perpendicularly to the front face of the resilient supporting sheet, greater than the depth of the first side upright and of the top and bottom cross-members;
the first side upright and the top and bottom cross-members are made from a single piece of tube that is substantially U-shaped;
the side plate has a rear edge and a front edge for facing the back of the user, said front edge being substantially identical in shape to the first side upright;
the side plate has an outside face facing away from the first side upright, the outside face having first and second series of hooks, and the second side edges of the front and rear faces of the resilient supporting sheet having respective first and second series of hems receiving respective first and second rigid rods which are fixed to the first and second series of hooks by the resilient return force exerted by the front and rear faces of the resilient supporting sheet;
the side plate has a top end and a bottom end relatively welded to the top cross-members and to the bottom cross-members; and
the side plate is covered by a protective cover-plate.